clk: fix mux clock documentation

The mux documentation mentions the non-existing parameter width instead
of mask, so just sed this.

The table field is missing in the documentation of clk_mux.
Add a small blurb explaining what it is

Fixes: 9d9f78ed9af0 ("clk: basic clock hardware types")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

include/linux/clk-provider.h

@@ -450,8 +450,9 @@ void clk_hw_unregister_divider(struct clk_hw *hw);
  *
  * @hw:		handle between common and hardware-specific interfaces
  * @reg:	register controlling multiplexer
+ * @table:	array of register values corresponding to the parent index
  * @shift:	shift to multiplexer bit field
- * @width:	width of mutliplexer bit field
+ * @mask:	mask of mutliplexer bit field
  * @flags:	hardware-specific flags
  * @lock:	register lock
  *